Bar codes have heretofore been widely used for a variety of kinds of products to display product information such as date of production, names of the manufacturers and distributors, expiration dates, etc. Here, to read the coded information of bar codes by using a reader, the surface on where the bar codes are printed must be flat. Therefore, in the field of packing materials such as bottles and caps, limitation is imposed on the surface on where the bar codes are printed and also on the quantity of information that can be encoded.
In recent years, therefore, it is a trend to utilize the technology of displaying information by using an IC tag. Namely, the IC tag is also called RFID (radio frequency identifier), and is a very small communication terminal in the form of a tag that includes an IC chip storing predetermined information buried together with an antenna in a dielectric material such as resin or glass. The IC tag is for reading out product information stored in the IC chip byway of radio communication. A memory in the IC chip is capable of storing the data of, for example, several hundreds of bytes offering such an advantage that a lot of product information can be stored therein. Further, the IC tag is capable of reading out the recorded information in a non-contacting manner and is free of such a problem as wear caused by contact. Besides, it has such an advantage as being realized in a form that meets the form of the product and in small size and in reduced thickness.
A patent document 1, for example, discloses a cap having an IC tag buried in a top plate thereof when the cap is opened.
There has been proposed to use the above IC tag for displaying the history of unsealing of the container. For example, a patent document 2 discloses a method of detecting the unsealing relying on the breakage of the lead wire that connects the IC chip to the antenna in the IC tag.
Further, a patent document 3 discloses an art of recognizing the fact of unsealing based on that an antenna provided in the cap body is broken accompanying the unsealing of the upper lid coupled to the cap body that is fitted onto the container mouth portion.
According to these patent documents 2 and 3, the fact that the IC tag is broken is detected by an external reader device to recognize the fact of unsealing still leaving, however, a problem that must be solved.
According to the art proposed in the patent document 2, for instance, the IC chip of the IC tag is provided in the container body or in a portion belonging to the container body (concretely, in a tamper evidence band that is cut off from the cap when it is opened), the antenna and the lead wire are provided in a cap that is fitted by screw onto the container body, and the lead wire is broken when the cap is unsealed.
When the container body is to be provided with the IC chip, on the other hand, the antenna and the lead wire that connects the IC chip to the antenna are provided in the cap which is separate from the container. In fact, however, it can be said that this constitution cannot be implemented. This is because, the cap is provided with the IC tag of which the antenna and the IC chip are connected together through the lead wire. The cap is then fitted onto the container mouth portion and, thereafter, the IC chip portion only is stuck onto the container. In this case, however, the cap must be fitted onto the container mouth portion in a state where the IC chip is hanging down requiring a very cumbersome operation (capping operation) accompanied by such a probability that the IC chip and the lead wire are liable to be broken during the capping operation. Besides, it is not easy to stick the IC chip hanging down from the cap onto the container.
Further, in case the IC chip is provided on the tamper evidence band (TE band) that will be separated away from the cap when it is opened, difficulty is involved in fitting the IC chip on the TE band. More than that, it is not allowed to sufficiently prove the fact of unsealing based on the breakage of the lead wire that connects the IC chip to the antenna. That is, in this case, the breakage of the IC tag stands for the separation of the TE band, and the TE band that is separated away proves the history of unsealing of the cap. It will, therefore, be understood that the history of unsealing of the cap is proved by the separation of the TE band despite the history of unsealing has not been proved by the breakage of the IC tag.
According to the means of the patent document 3, furthermore, the IC tag is provided on a lid member that is separate from a lid member that is sealing the container mouth portion, and the lid member sealing the container mouth portion is unsealed quite separately from the operation for breaking the IC tag of the lid member in which the IC tag has been provided. That is, to unseal the container mouth portion according to the patent document 3, the IC tag must be broken in advance separately from the unsealing operation and, besides, the lid member (outer lid) that has the IC tag must be removed requiring, therefore, clumsy operation for unsealing the container mouth portion and, therefore, further improvements have been desired.
According to the known means of the patent documents 2 and 3, further, it is not allowed to read the information stored in the IC chip after the unsealing, posing limitation on the use of the IC tags.